fixed drop/create database bug when holding global read lock

preserve originating server id in Intvar events to avoid inifinite loops


include/mysqld_error.h:
  new error messages
mysql-test/r/drop.result:
  updated result
mysql-test/r/flush.result:
  updated result
mysql-test/t/drop.test:
  test for proper handling of drop/create database when holding
  global read lock
mysql-test/t/flush.test:
  test to see if other thread would block on drop database if we
  are holding global read lock
sql/log.cc:
  preserve originating server id in Intvar log event
sql/share/czech/errmsg.txt:
  new error messages
sql/share/danish/errmsg.txt:
  new error messages
sql/share/dutch/errmsg.txt:
  new error messages
sql/share/english/errmsg.txt:
  new error messages
sql/share/estonian/errmsg.txt:
  new error messages
sql/share/french/errmsg.txt:
  new error messages
sql/share/german/errmsg.txt:
  new error messages
sql/share/greek/errmsg.txt:
  new error messages
sql/share/hungarian/errmsg.txt:
  new error messages
sql/share/italian/errmsg.txt:
  new error messages
sql/share/japanese/errmsg.txt:
  new error messages
sql/share/korean/errmsg.txt:
  new error messages
sql/share/norwegian-ny/errmsg.txt:
  new error messages
sql/share/norwegian/errmsg.txt:
  new error messages
sql/share/polish/errmsg.txt:
  new error messages
sql/share/portuguese/errmsg.txt:
  new error messages
sql/share/romanian/errmsg.txt:
  new error messages
sql/share/russian/errmsg.txt:
  new error messages
sql/share/slovak/errmsg.txt:
  new error messages
sql/share/spanish/errmsg.txt:
  new error messages
sql/share/swedish/errmsg.txt:
  new error messages
sql/slave.cc:
  fixed typo in comment
sql/sql_db.cc:
  global read lock should block drop/create database

1 files changed, 46 insertions, 0 deletions

diff --git a/sql/sql_db.cc b/sql/sql_db.cc
index 5243498f7fc..7cd892f6079 100644
--- a/sql/sql_db.cc
+++ b/sql/sql_db.cc
@@ -38,6 +38,32 @@ void mysql_create_db(THD *thd, char *db, uint create_options)
   DBUG_ENTER("mysql_create_db");
   
   VOID(pthread_mutex_lock(&LOCK_mysql_create_db));
+  VOID(pthread_mutex_lock(&LOCK_open));
+
+  // do not create database if another thread is holding read lock
+  if (global_read_lock)
+  {
+    if (thd->global_read_lock)
+    {
+      net_printf(&thd->net, ER_CREATE_DB_WITH_READ_LOCK);
+      VOID(pthread_mutex_unlock(&LOCK_open));
+      goto exit;
+    }
+    while (global_read_lock && ! thd->killed)
+    {
+      (void) pthread_cond_wait(&COND_refresh,&LOCK_open);
+    }
+    
+    if (thd->killed)
+    {
+      net_printf(&thd->net, ER_SERVER_SHUTDOWN);
+      VOID(pthread_mutex_unlock(&LOCK_open));
+      goto exit;
+    }
+
+  }
+  
+  VOID(pthread_mutex_unlock(&LOCK_open));
 
   /* Check directory */
   (void)sprintf(path,"%s/%s", mysql_data_home, db);
@@ -105,6 +131,26 @@ void mysql_rm_db(THD *thd,char *db,bool if_exists)
   VOID(pthread_mutex_lock(&LOCK_mysql_create_db));
   VOID(pthread_mutex_lock(&LOCK_open));
 
+  // do not drop database if another thread is holding read lock
+  if (global_read_lock)
+  {
+    if (thd->global_read_lock)
+    {
+      net_printf(&thd->net, ER_DROP_DB_WITH_READ_LOCK);
+      goto exit;
+    }
+    while (global_read_lock && ! thd->killed)
+    {
+      (void) pthread_cond_wait(&COND_refresh,&LOCK_open);
+    }
+
+    if (thd->killed)
+    {
+      net_printf(&thd->net, ER_SERVER_SHUTDOWN);
+      goto exit;
+    }
+  }
+
   (void) sprintf(path,"%s/%s",mysql_data_home,db);
   unpack_dirname(path,path);			// Convert if not unix
   /* See if the directory exists */